SINE -LINK
га
TIMER SINCLAIR USERS CLUB
| NEWSLETTER
Toronto, Опіагіо |
EXECUTIVE OFFICERS
PRESIDENT: George Chambers (416) 751-7559
LIBRARIAN: Martin Mauk - tapes John Burns - magazines
ASS'T LIBRARIANS: D. Cooper `
T. Haller
TREASURER: Greg Lloyd
NEWS EDITORS: John Roach (416) 447-7784
ACTIVITY DIRECTOR: Cameron Hayne
LIAISON OFFICER (Out-of-town members): George Chambers
Mike Mitchell
LETTER FROM THE PRESIDENT
Over the past couple of months we have had quite a few new members
join our club, I am sure they hope to benefit from association with
other T/S users, and often their hopes are realized. However, in the
rush of things, I am sure some of them tend to get lost in the shuffle,
and ultimately lost to the club.
I would like to take this opportunity to welcome each and every
one of you to our club, Use it, ask questions at meetings, borrow
from our library, read the newsletter. Not the least important,
contribute to the club activities. From my experience, you will profit
immensely from the give and take of a more active role in the club.
The invitation is extended; seize it. Cameron Hayne has done this,
and has agreed to be our new Activities Director. He will be responsible
for providing the demo's, talks, etc. at each meeting. Welcome to the
executive, Cameron. We're pleased to have you.
Yours in computing
George Chambers
(President)
NOTES FROM THE EDITOR
If you have an article you would like published in the newsletter,
give it to any member of the executive during the meeting or mail
it to SINC-LINK c/o J. Roach, 56 Pachino Blvd., Scarborough, Ontario
MIR 4J7.
Dan Sauve reports that nobody showed up at the 2 get-togethers he
called to form a hardware SIG. He's still enthused - call him at
251-5623 if you're interested.
SYNCBITS
Ian Robertson
UPDATE FROM LAST ISSUE: It appears that someone is working on
a 3TS2068/5PECTRUM interface. Apparently it is àa lot more
complicated than simply changing bus configuration. Aerco
(Austin Texas) is marketing a great looking TS2068 Disc System.
Bottom line is 508.00 (US) for this complete 2 drive system
with cabinet and 64k Ram/Bk Rom onboard. For details see their
advert. in latest issue (HII) of T-S Horizons.
U.K. NEWS! Two interesting items gleaned from recent issues of
Your Computer; а) a survey of 23,000 Open University students
with home micros indicated that Spectrum was no. 2 with 15% and
that the ZX81 was no. 3 with 11% (of further interest was the
face that the CBM 64 was 4th with 6% and the Apple was tied with
the Т19 at 4%), b) a comparison between the BBC and the QL
which makes us dedicated Sinclair types cringe a little, as the
BBC comes out ahead.
T82068: There are several enterprising programmers. advertising
enhancements for the TS2050 Modem MTERM software which received
such bad reviews because of the Documentation (ог rather,the
lack of it). Did you know that the Spectrum version of Tasword
II does NOT WORK with the TS2068 with Spectrum Rom. It does not
print out! Conversely, during a conversation with 21st Century
Electronics I was advised that a 152068 program which worked
with the Spectrum Rom (inside a 152068) did not work on the
Spectrum. Verrry interesting.
TS 1000: If there still are some dedicated users out there, I
suggest that if you want to purchase hardware items still
advertised, that you get cracking. They will not be around
forever. There are quite a few items available in the П.К. or
from Integrated Data Systems (who carries most of the U.K.
items). John Oliger is still offering his Hi-Res with colour
kit.
SPECTRUM ROM: 0+ all the games reviewed I must say that SABRE
WULF by Ultimate is the best (in my opinion that ix). Two others
deserve honourable mention, Jet Set Willy and Kokotoni Wilf. All
three make good use 0+ graphic capabilities, The following
languages are available for the Spectrum: Forth (several
versions), Beta Basic (enhanced Basic), Pascal, C, Micro Prolog,
Logo and Lisp.
MAIL ORDER FROM U.K.: Most U.K. prices quoted in magazines
are "Inclusive" or "Inclusive of VAT". VAT is a value added tax
of 13% on top of the item price. Therefore deduct VAT from the
quoted "Inclusive" price (multiplier .885) and add appropriate
postage. On cassettes add approx. (2.00 each, to a total of 4,
then add £0.75 for each additional. For larger items always add
a тіп. of £5.00 to £7.50. Airmail costs are incredible, і.е. р
£7.50 for a £mall item (if larger than standard envelope size).
COMPUTERS AREN'T HUMAN
Most humans use the decimal system, which consists of ten digits (0, 1, 2, 3, 4, 5,
6, 7,,8, 9), because humans have ten fingers. The computer does not have fingers,
so it prefers other number systems instead. Неге they are....
5 | BINARY
Look at these powers of 2:
29 =1
21 = 2
22 = 4
23-8
2" = 16
25 » 32
28 = 64
Now try an experiment: pick your favorite positive integer, and try to write it
as а sum of powers of 2, For example, suppose you pick 45. You can write it as
32+8+4+1. Suppose you pick 74; you can write it as 64+8+2. Suppose you pick 77;
you can write it as 64+8+4+1. Every positive integer can be written as a sum of
powers of 2.
Let's put those examples in a table:
ORIGINAL WRITTEN AS A SUM DOES THE SUM CONTAIN...
. NUMBER OF POWERS OF 2 647 32? 16? 8? 4? 2? 1?
15 52+8+4+1 no yes no yes yes no yes
174 644842 es no no es no es no
es
64+8+4+1 es no то es yes no
To write those numbers in the inary зузфет, replace "по" by 0 and "yes" by 1:
DECIMAL SYSTEM BINARY SYSTEM
45 or simply 101101
/ г 0
The Деетта,. Bye ber uses the digits 0,
columns:
thousands hundreds tens units
For example, the decimal number 7105 means "7 thousands + 1 hundred + 0 tens + 5 units".
The binary system uses only the digits 0 and 1, and uses these columns:
sixty-fours thirty-twos sixteens eights fours twos wits
‘For example, the binary number 1001101 means "1 sixty-four + 0 thirty-twos + 0 sixteens +
1 eight + 1 four + 0 twos + 1 unit"; in other words, it means seventy-seven.
In elementary school, you were taught how to do arithmetic in the decimal system.
You had to memorize the addition and multiplication tables:
DECIMAL ADDITION DECIMAL MULTIPLICATION
3 4 5 6 7 9 0 1 2 4 5 6 7 8
» 2, 3, 4, 5, 6, 7, 8, and 9 and uses these
?
3
0
5
юы C UO Rt N PB
mw CS i = C4 bor
^ атп
9 10 11 12
oO) C Un i LA Jom C
0
0
1
2
5
4
5
6
7
8
9
2 09 МС CD hut! ©
10 11 12 15
In the binary system, the only digits are 0 and 1, so the tables are briefer:
BINARY ADDITION BINARY MULTIPLICATION
| 0
0 1 i 1
0 ofo o
11100 &босацзе доо is witten 110 1
"10" <n binary
If society had adopted the binary system instead of the decimal system, you would
have been spared many hours of memorization!
Usually, when you ask the computer to perform a computation, it converts your
numbers from the decimal system to the binary system, performs the computation by
using the binary addition and multiplication tables, and then converts the answer
from the binary system to the decimal system, so you can read it. For example,
if you ask the computer to print 45+74, it will do this:
45 converted to binary is 101101
*74 converted to binary is *1001010
Eu 1110111 converted to decimal is 119
Dame usd
The conversion from decimal to binary and then back to decimal is slow. But the
computation itself (in this case, addition) is quick, since the binary addition
table is so simple. The only times the computer must convert is during input
(decimal to binary) and output (binary to decimal). The rest of the execution is
performed quickly, entirely in binary.
You know fractions can be written in the decimal system, by using these columns:
units point tenths hundredths thousandths
For example, i2 gun be written as 1.625, which means "1 unit * 6 tenths * 2 hundredths *
8
5 thousandths".
To write fractions in the binary system, use these columns instead:
units point halves fourths eighths
For example, 12 is written in binary as 1.101, which means "1 unit * 1 half + 0 fourths +
1 eighth".
You know i is written in the decimal system às 0.3333333..., which unfortunately
s : i : : 1, :
never terminates. In the binary system, the situation is no better: zis written
as 0.010101.... Since the computer stores only a finite number of digits, it cannot
1 EST :
store = accurately—it stores only an approximation.
A more distressing example is т. In the decimal system, it's .2, but in the binary
system it's .0011001100110011.... So the computer can't handle = accurately, even
though a human can.
Suppose you enter this on your ZX-81l computer:
PRINT "MY FAVORITE NUMBER IS ";4.001-4
The computer will try to convert 4.001 to binary. Unfortunately, it can't be con-
verted exactly; the computer's binary approximation of it is slightly too small.
The computer's final answer to 4.001-4 is therefore slightly less then the correct
answer. Instead of printing MY FAVORITE NUMBER IS .001, the computer will print
MY FAVOURATE NUMBER IS .0010000002 . Other computers come up with numbers like
.000999987 ,
To test your 7Х-81'5 accuracy, try 4.0001-4, and 4.00001-4, and 4.000001-4 etc.
you might be surprised at its answers.
ALL 2 nd Zrectrum prearams TERRE REN Е _
эге i ÁJrecorded an tape if PROGRAMS STRUCTURE
one n2 e бєгїп. These
FRETA am ве Figure zhows some Of the
^2 iproaram) Easit tion of a Prearam. ALL
EN TELES] of the сагат would be on tape
oy т SBE iii fated ih Fiaufre 2.
IHE CODE (butes) This i typical G-section
5 ргоага ith basic, screen and
Basic Programe мша! | iust tade. LE Line ЭЙ whith i5 the
have a bazic section but save | » FLL programs „Жш.
С machine code rroarzinz have 2 ar a LWA MS WE а SANE line,
; 8 sections, These could include this o! the basic is saved bu
| the bazit Section, maybe a Em diee "T 7
| Ае and at Least one code ZOUE "example" LINE 20
== :
ECU This means that whem the saved
| REDATE is loaded, it ш
\ automaticatlu ag to Line AO.
| herefore ine ZU if cattle &
! PERDER autoestart Line CF S bon ts
| мег sertian nn tape it Line 2а instructs ta L "s"
геа а bs a header. This is SCREEMS so that the. screen wilt
the short part that loads when load while the tape is still
the border shows blue & red running, Then line 39 will Гоар
stripes. After a header has mc" which are the machine Code
Loaded, the.title of the bytes. This is the tast section
section mitt Usually appear on fo be Loaded zo line 40 PRINTS
screen, Besides the title, the а message to stop the tape
header also Loads im the length Plauer,
and starting address of the
eection, The rest of the program is then
ExXECULEd and somewhere in the
basic there will be an
instruction to access the
machine code that was
previousLu Loaded. (This if done
With the USR command), As the
header af gath section uas
loaded. the screen would have
disrigsued Figure 3, however,
a SCREENS would cover up part
FIGUGE of ait.
LORD "s" SCREENS
LORE "me" CODE
FIGURE 2
г
PLS : PRINT "Stop Tape"
etic..etct......
Maw
4 uu enm ia =ч
yam dn onm] dno
мита
m zu meu
In em Ке Жы"
c niu
Oc?»
(Basic Program)
STOP
FIGURE 3
SAVE “Еехамтр|е” LINE 20:
"s" SCREENS: SALVE "mc'"CODE
STOP Program: example
bytes: Е
bytes:
me
зи.
г шоп t i ace
or the basic wie
L sin а TAVE line рне ki xeu
and not know where the LUR CODE
su UR Mer n iD pot erase this from youi
compzter Stree 1
То LL these Problems, we аж
us isl utility program Immiiistziu atop the tape
tt iz ия 2 Load a header thi: point. — ы йы
ari it and it gives us кат om
ali the required information. ————
One such utility is called Е ны
"Header". TO USE it we first р ое
load it in and just Follow the = .
directions on the screen. The SAVE "="
header Gf each section is шы Е
loaded in with "Header" and we HOTE 3 =f |
Сап read the needed info on the АРЕ
sereen andor iet the printer fis: E
ОИ Therefor
saved it
SAVE "2" CODE 16364,6912
6. LORD in the last section
(machine code) from the
LET’S TRY IT Original tape With:
LORD "" CODE
1, We Mill make = back-up oF
ihe proaram in Figure 1, The Ts Gave Fi: rode and indicat
First ziep is te Ghtain the the sddrezz it is to be pui
following information amd the Length or it.
+Наме of esch section, ZAVE "mc" CODE 40000,1208
&Huto-ztart iine GF basic,
Stapi address of each code In the Sample the 48000 is
E£&ciion, and fus Je TE ар of En
| code ап 2ай is е numbe;
xLenath of each COde section Se Rule Cono 1s e ERE
If this cannot be recadillu must be included Whenever
obtained bu looking for the faving code,
fgve Line in the basic, then
YOU must use a special $. If the program has more
utilitu such as "Header". sections just repeat the
E procedure for the extras,.ai
2. How Load in only the basic if there are fewer, omit
section of the Proaram in those. How you mag Wish to
one of tuo ways., Ome Way is verify everything using:
te LORD "" and BREAK when it [n
has Loaded the first section WERIFY ""
In zome Programs чои may |
na Е арїє io BEZAR, For . io check the basic and:
these uou myst toad them "m
using: НЕРСЕ "". This will VERIFY "" CODE
Cauze & break automatically .
at the end of the first fhe code. vou can
section. Tru to stop the У the SCREENS за
tape player right at the end over at when
Gf this Bection ЕС that it
is positioned at the start
Gf the second section.
3. This bassiC Can now be saved
onto your back-up tape bu:
НЫЕ "example" LINE 20
PROGESHH ING TRICKS
us БЕ using the Sane
ThE titi Of the basic program E Griginet unless
MILL aiu dz Frint on screen = the proaram
When 115 header is logged, but nasmez.
the titie of i OF OL Lona
ЕС: ИЕ if = times not =. 2 in doubt whether
shown, This i done bu makina ЕС: ПМ is Е agren
the ink Sand paper the rise or Пе code, Load it
colour before that section i£ With: LOADS "" CODE
loaded. Obtain the hidden title .
bu the wee of "Header", =. £times uou will not need
use the Header Utility.
When the basic section if 2 Programs have all the
loaded and you with to BREAK etsay info in 8 Save.
the loading process at the end = in the basic section,
Of the section, uou may ae a
crash of it mau keep an 4. When faving a screen, it
loading. This trick is done by ИНЕТ БЕ Present on the Tu
a FORE in ThE suto-start Line Screen nr it Will Mot save,
Or Бч the ON ERR command, :
Overcome this problem bu load- 5. If the basic has а save Line
ind the basic With the MERGE uot can GOTO this Line te
Command. Save all sectione but Note
| #4 applies. When Saving more
Sometimes there is a blank area than one section by using
Of tape between sections. This the fave Ling, be ready ta
WoUld be needed for the basic Press a key when Prompted.
46 do something before the Line |
that loads the next section, $. Mote that throvahout this
For €. amt LE, the “Upload Оса" Srticle, I have used the
Program dots a short display term "back-up" в: opposed tn
ГРИН СЕ ЕЛ the basic and 5 "copy", Even though we are
thé Machine code. Be sure to desting With Making as copy
ameert this came tenath СЕ nr cupLicate nf an original
tlàn! im your baàtk-UuP. YOU can Program, ihe term "back-up"
determine this lenath bu timina haz 3 more legat fring to jt!
st or With the tape counter,
Integrated Data Systems
30 Brookmount Road, Toronto, Ontario IL ЗМІ
416-443-5518 (Answer-phone)
Please note that we have moved and that the above is our new
address and phone number. We still have а full catalogue of
ZXB8':/TS:1000 items although this is decreasing all of the time.
We have publication rights to software from Ezra Group II,
Hargrave, Woods plus other authors under our own name. We alsn
believe that we are the Only company in North America selling
Centronics and RS232C Interfaces that are port mapped not memory
mapped, The Dual Centronics is $89 and the Dual RS232C is $149.
Both come with
along with
evailable.
2958’ s can all
EPROM Poards
software on
and some of
$24.96. TS1829'5,
be provided
on consignment,
We scrept
wriless there
printsez
VISA, Mt
ere books where it is +5, or
nr modems.
tape but we can alse provide on EPROM
the most useful utilities
We also carry books such as Mastering MC at
and RDM Disassembly ARB at
$15.99
TS RAMS 2949? and
Piss some used equipment that we sel]
2
or cheques and charge 1,50 PRH/order
+5 if computers,
A HEADER РЕОБРАМ FOR THE
When I 954 mu
thought one of i
things about it
program buy г
the name of
on-screen а
it started
the ZXB8l ha
uould be ma
Where have Т
time? I've oniu
there is a progr
Practically the
is to be found i
book Explorers
ZX81'. Hou I ney
ILL never know,
b
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USE OF THE 7 IN FUNCTION
ju G Е Chambers
It is sometimes desirable to be
able to use tuo keys at ihe _
same time, Many games could be
improved with this Capabilities
On the Т52958 this 1% BOGS sins
through the use of ine 'IH
function.The fol lowing Table Я,
and Ftch-a-Sketch demonstration
program till illustrate this
possibility.
IN
Зот BR SH H N E
49158 ENTER L К. a H
57340 Р ü
e
43486 à
oe
>
a
fé
к
к
Te
л
ad
E
[Ly
5 РЕМ
T
an ETC KA-SKETTH ТУРЕ
of drauing routine ta
illustrate the USE oF
the IN runct
the Т52 058
Б БЕН _
T REM Bu G
а RE р =
а REM Use key a
rar cur А
lise КЄ
Ноа: ce H
18 LET x=125: LET =a E
2A IF IN 54510 -30 AND yilve TH
EH LET yeuystl ==
зв IF IN 55022 =за AND yuri THEN
zu-:
ETGS42 =ЗА AND imma TH
7348 2228 ANG xii THEN
SALES 4:31 THEN GO 305
aa
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п ze
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t-Cc/2: LET parti: IF c
п TO ва
о 14а _ _ ۶
HEEYHE:"" THERM Go ТО Б
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Ti
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ti
uh to ЕГЗЕЕ а
tar = 3 bulk
eras af away should
it b other tapes?
Arte = number of
EXPE oncluded that
ther = major cancern
РОГ rasure of
prog img, is а List
or t {t= Which did
not ect on a short
prz- aram.
x Hoving s head-demagni fier
around the tape,
+
Pep
"ап
a e
e
+
ЕГ oJI
=
тз
x
u
antact with colour
hile it was turned
m
fuk a
к=
бегл
т
11
Dm
1
ME
+
>. =
[nad vt
m
tape under a telephone
it rang 5 times.
SCREEN COPIES on the
inter with tape in
With printer.
+ Held tase about 1 (ONE) inch
From bulk tape eraser while
turning eraser orf & оп and
mawvina tape around!!!
Я kargar zresnker 3 t [ e.a!
B nr.) would pro erase the
(rogram, Likewis ing the
tape within 1" û bulk
eraser ji: “Goodby aram":
eyen if the eras switched
on & OFF nce Н: ‚ this if
nat cons = a tal.
Sa why b baut.
erasing = program?
The real sguzeée ror
Lost ora careless
finger б Button.
41 T1
Du
IS
SPECTRUM TS 2068
BOTTOM TOP BOTTOM TOP
GND GND
SPKR/ TAPE EAR
+15 v ATR
+ бу 0,
N.C. N.C.
PWR GND Do
PWR GND
{ CLK t
i Ao L]
| ^, ,
| А, 3
i А» 4
i А. В INT
АВ AMI
А.В НАСТ
A MREQB
А, юкаВ
А, RDB
As WRB
As BUSAK
А, WAIT
А, BUSRQ
А, RESET
А. MI
N.C RFSHB
RGB Red EXROM
RGB Grn ROSCS
RGB Blu BE
BOTTOM
SIDE B
ZX - 8l
ROMCS
TOP
7 МЕЛ Hardware Meus
by Peter N°Mullin for ТЕ. С. 27/85 #1 in a Series for the ADVENTUROUS, COMMITTED 7X8! Owner.
took advantage of the great price on GLADSTONE 64K RAM packs
isable the 8K-16K block, so they can use
some of the many peripherals which are mapped to that area. To this end,
I have drawn an improved schematic of the 664К for reference, and written
an article, with documented schematics, outlining the necessary procedures.
А simple address decoder and MREG NOT gating does the trick.
with options depending on required switching flexibility. In fact, although
not mentioned in the article, this method could be used to selectively
disable ANY block of memory between O & 64k! |
The details are too involved to relate here, sa I have placed copies
of the project manual in the CLUB LIBRARY: it is available there
for those who require it.
Many who
have expressed the need to d
or info on using the cheap but nifty
EXCELTRONIX 5" Greenscreen monitor. (I just found the file:) | |
The problem is with the supplied sync separator, NOT with the monitor itself.
My solution involves using the partial sync-separation provided by the |
Random Access VIDEO INVERTER circuit, which was published as a construction
project in Computers k Electronics, May 'B83 issue. А5 with the G564K project,
l will place full details in the LIBRARY as soon as I can prepare the material.
Apologies to those waiting f
erm
Т am composing this text on my 64K 7Х81. outfitted with a surplus Appl
lone keyboard, using Word Sinc II. Text is output on an EPSON MX-BO printer,
іа the EPROM SERVICES Centronics interface and software driver,
hich 1 recently purchased fron Integrated Data Systems.
ft 4u encouraging to report that MEMDCALC, and ZX PRO-FILE (Centronics
JE чето) both print out just fine with the EPROM SERVICES I/F and software.
utput of the printer CTRL and «ESC- codes, so valuable ín wordprocessing,
з a sticky subject, though. I BREAK from WSII menu, t LFRINT At to do it here.
I am currently awaiting replies from both P. Hargrave and EPROM SERVICES
regarding WSII.4 compatibility. Things seem promising, so I^11 keep you posted.
My final topic for this issue is the most exciting.
I recently received documentation on the long-awaited ZXB1 Video Upgrade
project, created by John Dliger, 11601 Whidbey Dr., Cumberland, IN 46229.
The following features should make you sit up and take notice:
1) SLOW mode is 5.5X normal speed. i.e. same as 2068. Some M/C games
run TOO FAST, and arcade-speed games in BASIC become possible!
FAST mode, as usual at 6X normal SLOW speed, is BLINK-FREE!
2) You get COLOUR VIDEO with UPPER and lower case on screen, as an
alternative to inverse characters. Colour control is equiv. to 2068.
з) Machine code can now run anywhere in 464K, with free use of the IX register,
and schemes using vectored hardware Interrupts may be supported.
4) System is completely transparent to existing software.
5) Display File CRASHES are NO HORE!
The project consists of two circuit boards. one for the TMS9718 Video
Display Processor (which supports SFRITE graphics) and 16K Video RAM.
The other circuit board holds an enhanced(i.e. display routines rewritten)
versian of the ZXB1 ROM, which it overrides. А Motherboard оғ" cable is required.
Mr. Oliger sells both boards, and all parts except the VDP and it s crystal
for $48.95 U.S. (Quick! Where's my checkbook?) Write to him for details. |
Discoveries like these make the AERCO Disk System for the ZX81
seem more attractive all the time to a hardware addict like me.
But that's for another discussion. Ho рух Com pat Хр"
